In a Multi Protocol Label Switching (MPLS) network, incoming packets are assigned a label by a Label Edge Router (LER). Packets are forwarded along a Label Switched Path (LSP) where each Label Switching Router (LSR) makes forwarding decisions based solely on the contents of the label. At each hop, the LSR strips off the existing label and assigns a new label which informs the next hop how to forward the packet.
A Label Switching Path (LSP) can be used for a number of purposes, such as guaranteeing a certain level of performance, routing packets around congested portions of a network, or creating IP tunnels for a virtual private network (VPN).
In the context of establishing a virtual private network, the prior-art approach to VPN multicasting is to instantiate large amounts of state in the core. Furthermore, VPN multicasting offers little or no service assurance or tools for OAM (Operations, Administration and Maintenance).
Accordingly, it would be highly desirable to provide a virtual private network that does not instantiate large amounts of state in the core, and that furthermore offers service assurance and OAM tools.